22 replies to this topic

[Neddy]

Hi,

 

For a torsen (T1) LSD in a 1.8 Miata diff, do I want redline 75w-90 or redline 75w90NS?

 

Cheers.

[Ron Alan]

I was told by the rep NS but I would bet either are fine.

[FTodaro]

NS

[davew]

I use regular

[Jim Drago]

unleaded

[davew]

ethel

[Johnny D]

Merman

[Ron Alan]

Merman

Nah...Fred

[Tom Sager]

Nah...Fred

Yabba dabba doo

[Ron Alan]

Yabba dabba doo

Nah...that would be Wilma! 

 

I was thinking more Lucy and Ricky!

[Neddy]

haha. pretty soon we'll be cutting holes in the floor for pedal power!

 

I'll take it as both regular and NS are fine in a torsen....???

[Bench Racer]

I was thinking more Lucy and Ricky!

[steveracer]

Gotta go with Sinatra.

[Tom Sager]

haha. pretty soon we'll be cutting holes in the floor for pedal power!

 

I'll take it as both regular and NS are fine in a torsen....???

I think you'll find people use either one.  The NS fluid is formulated to reduce slippage a bit which might slightly reduce wheelspin if you experience that on the track. 

[ChrisA]

Gotta go with Sinatra.

Ethel Sinatra? Who is that!?!

[Johnny D]

Yabba dabba doo

Is he related to Scooby doo ??
J~

[Tom Sager]

Is he related to Scooby doo ??
J~

Hard to say.  There are several centuries separating them. 

 

I vote for the NS fluid though. 

[steveracer]

Ethel Sinatra? Who is that!?!

Frank's Momma

[SaulSpeedwell]

Your T-1 Torsen partially (largely) depends on internal friction between the side gears and the case to achieve its TBR (Torque Bias Ratio).  For a T-2 Torsen, the helical gears and side gears both partially (largely) rely on internal friction to achieve its true TBR.  It may not be widely known, but it is nonetheless publically published that lower viscosity and higher friction fluids will increase the "lockup" of your Torsen.  The problem is the same fluid is lubricating your bearings and ring and pinion.

 

Note:  LSD additive reduces friction to avoid chatter, it doesn't make the LSD "grab more"

 

Worst case:  Shockproof fluids (turns to "grease" in the Torsen thrust washers and any other mating surfaces of LSD "clutches"), Mobil 1 synthetic gear oil (super slick!  not good for transmission synchros or friction-dependent LSDs).

 

Good choice:  Redline 75W90NS, or any non-LSD-additive GL-4 or GL-5 gear oil.  Heavy truck gear oils (Mobil Delvac, Wolf's Head HDX, etc.) are great choices and very economical.  If it is good enough for $250K trucks pulling 3 trailers, it is good enough for your Spec Commuter Convertible!

 

Max lockup, minimum drag, questionable long-term reliability choice:  ATF or ATF-like transaxle oils  and "gear oils".  The holy grail would be a GL-4 (or GL-5) rated fluid with ATF-similar viscosity and ATF-similar shear friction at mating clutch faces.  There are "boutique" custom blends available to achieve this, but also much cheaper easier-access fluids that will achieve most of the gain for much less hassle and cost.

 

Runoffs Polesitter:  0 weight Gorilla Glue 

[davew]

 

 

Runoffs Polesitter:  0 weight Gorilla Glue 

 

Back in the old days of points/condensors and bias ply tires, I was told a trick to cure a noisey diff was to put a banana peel inside the housing before adding fluid. Somethings never change